Valve stem grinding fixture



Dec. 5, 1939. F. o. ALBERTSON 2,182,191

VALVE STEM GRINDING FIXTURE Original Filed Dec. 28, 1935 3 Sheets-Sheet l Dec. 5, 1939. F. o. ALBERTSON 2,132,191

VALVE sum GRINDING FIXTURE Original Filed Dec. 28, 19:55 3 Sheets-Sheet 2 Dec. 5, 1939. F, Q ALBE TSON 2,182,191

VALVE STEM GRINDING FIXTURE Original Fil ed Dec. 28, 1935 3 Sheets-Sheet 3 Patented Dec. 5, 1939 UNHTED STATES rarest creme;

VALVE STEM GRINDING FIXTURE Frans O. Albertson, Sioux City, Iowa, assignor to Albertson & Company, Inc., Sioux City, Iowa, a corporation of Iowa 6 Claims.

The present invention relates to valve stem grinding fixtures, and is particularly concerned with a fixture or attachment which is adapted to be used for grinding the valve stems of valves for internal combustion motors which do not have any provision for adjusting the length of the valve stem or the clearance at the valve other than by making the stem of predetermined length.

The present application is a division of my prior application, Ser. No. 56,438, filed December 28, 1935, on Valve stem grinding fixtures, now Patent No. 2,088,359, dated July 27, 1939, relating particularly to the gauge used with the fixture, while the present application relates to the grinding machine and method of grinding including such a fixture.

For example, the Ford motor cars, models A, B and V-8, have no provision for any adjustment of the valve clearance other than the making of the valve stem of such predetermined length that the valve will have the clearance desired, and the present fixture is particularly adapted tobe used upon valves for these motors.

However, it frequently happens in this out and try system that too much metal is removed from the end of the valve stem, thereby making the valve stem too short, so that that valve cannot be used, and a new valve must be substituted.

One of the objects of the present invention is the provision of an improved gauge by means of which valve stems for motors of the type described may be accurately fitted without any wastage, and with the desired valve clearance.

Another object of the invention is the provision of an improved gauge of the class described, by means of which the clearance is'automatically provided without any particular attention on the part of the operator except the setting of the gauge to the clearance desired.

Another object of the invention is the provision of a valve stem gauge of the class described which is more accurate than the devices of the prior art, more sturdy, more simple, and capable of faster grinding action, so that the valve stems may be fitted more quickly, accurately and economically with the present device than with the devices of the prior art.

Other objects and advantages of the invention will be apparent from the following description and the accompanying drawings, in which similar characters of reference indicate, similar parts throughout the several views.

The present fixture is particularly adapted to be used in connection with the grinder of valve grinding machines of the type disclosed in my prior Patents Nos. 1,722,880, Valve grinding machine, issued July 30, 1929, and 1,909,446, Valve grinding machine, issued May 16, 1933. I desire it to be understood, however, that the fixture and gauge may be used with various different types of grinders in which the proximity of the grinder to the fixture may be adjusted so as to grind off the stem of a valve to a length predetermined by the gauge.

Referring to the three sheets,

Fig. 1 is a top plan View of a complete installation showing fragments of the grinding machine and the whole fixture, with the gauge in gauging position;

Fig. 2 is a side elevational view of the same structure, except that a valve has been substituted for thegauge', showing the device in the grinding operation Fig; 3 is a vertical sectional view taken on the plane of the line 3.3 of'Fig. 1, showing the details of structure of the fixture and gauge;

Fig. 4 is a vertical sectional view, taken on the plane of the line 4- l of Fig. 2, showing other details of structure;

Fig. 5 is a fragmentary top plan view of the valve head as it is disposed in the fixture, during the grinding operation, showing how the device automatically provides a suitable valve clearance;

Fig. 6 Ba sectional view of the gauge, taken on the line 66 of Fig. 1, showing the indicia for indicating the amount of valve clearance.

Fig. '7 is a view in perspective of a grinding machine of which the present device is a part, as distinguished from a separate attachment.

Referring to the drawings, it indicates in its entirety the grinding machine, which is provided with a carriage l2, customarily used for movably supporting a chuck, as shown in the patents men tioned. The base 28 of the grinding machine also has a carriage for movably supporting the grinder assembly, which includes the grinding wheel By reference to the patents mentioned, which are hereby incorporated as a part of this disclosure, it will be found that the chuck carriage i2 is adapted to be moved transversely to the grinding wheel,- that is, upwardly and downwardly, in Fig. l, by means of an appropriate lever, while the grinder carriage, including the motor and grinding wheel Si], is adapted to be moved from left to right, and vice versa, in Fig. 1, by means of an appropriate crank, as shown in said patents,

The chuck carriage i2 is preferably provided with an upwardly projecting bolt I3 adapted to drawings, of which there are The fixture I! has its base I6 provided witha substantially flat bottom surface I 8 and with a transversely extending slot IQ for receiving the bolt l3. Slot l9 communicates with the outer border of the base by means of a communicating slot 2| which enables the fixture to be slid on the bolt I3 from the left in Fig. 1.

In order to assure the location of the fixture with its axis at right angles to the axis of the grinding wheel 35, the bottom surface l8 of the fixture base is provided with a transversely extending rib 22, which fits in a slot 23 in the chuck carriage 12.

It is thus a relatively simple matter to secure the present device in its proper position, arranged so that the cylindrical surface of grinding wheel 30 will grind the end of the valve stem with a fiat surface at right angles to the axis of the stem. The base It of the fixture if is provided with an upwardly extending portion or column 24 which supports a laterally projecting arm 25. The arm 25 has two upwardly projecting portions 26 and 2! which are adapted to support the forked members 28, 29. i

For this purpose, arm 21 is provided with a vertically extending slot 3| at the top for receiving the screw bolt 32 which passes through this slot and is threaded into the forked plate 29. Plate 29 comprises a substantially rectangular steel plate with a threaded bore 33 for bolt 32 and having a substantially V-shaped slot 34 at the top. The plate 28 may be identical in shape, but is provided with an unthreaded bore 35 through which extends the screw bolt 36, which is threaded into the threaded bore 31 in the arm 25.

Plate 28 is preferably located in a rabbeted recess 38 so as to have its lower edge engaging a shoulder 39 and to enable the single bolt 36 to secure plate 28 against rotation. It likewise has a V-shaped slot 34 at the top. The plate 29, having its bolt 32 secured in a slot 3|, the elevation of plate 29 may be so adjusted with respect to that of plate 28 that the slots 34 are adapted to hold a valve stem in level position or in such position that they are at right angles to a tangent of the periphery of the grinding wheel 30 at the point of contact.

The fixture so far described comprises all of the parts necessary for the support of the gauge or valve stem on the grinding machine in grinding position or otherwise, and I shall now proceed to describe the further features which enable the determination of the length of the stem.

The fixture is preferably provided with a gauge unit, which is indicated by the numeral 45, and this gauge unit comprises a dummy stem 4! and a gauge head 42. The dummy stem H is of substantially the same size as the valve stem of an engine of the type described; but, since the valve stem guides of such engines are removable, this dummy valve stem is preferably provided with a cylindrical enlargement 43 located to engage in the recesses or guides or bore which usually support the valve stem guide. The valve stem grinding attachment is preferably provided with several such dummy valve stems which may have enlargements 43 of different size for fitting in the places of the various valve stem guides.

In some embodiments of the invention the enlargements 43 may be totally omitted and the stem made of suitable size to fit in the guide itself. The dummy valve stem li is provided with substantially fiat end surfaces 44, 55 and is preferably made of a good quality of steel so that it may be accurately machined and so that it can be used as a part of a gauge.

The gauge head 42 may comprise a sleeve 46 having a cylindrical bore 47 adapted to slidably engage the reduced cylindrical part 58 of the dummy valve stem 410. Sleeve 55 has an exterior cylindrical surface 49 and may be provided at one end with a frusto-conical valve seat engaging surface 50 located upon a radially extending flange 5|.

Intermediate the flange 5! and the cylindrical outer surface =29 of sleeve 48 there is athreaded cylindrical portion 52 of sufiicient size so that the complementary threaded bore 53 of a stopengaging member 54 can pass over the cylindrical portion 49.

This stop-engaging member comprises an annular member having a knurled outer surface 55, the centrally located bore 53, a frusto-conical surface 55, and the fiat end surfaces 5?, 58. I The knurled outer surface 55 is adapted to be engaged by the fingers when this portion of the head is adjusted to provide the desired valve clearance.

The sleeve 46 also slidably supports a thrust member 55 which comprises another sleeve slidably mounted on the sleeve 45. Thrust member 59 has a frusto-conical surface 55, upon which are located the indicia and scale divisions of zero to fifty, or other appropriate divisions, depending upon the thread.

In the present embodiment the thread 52, 53 is such that a portion of a turn of the member 54 on. these threads moves it axially n the head 42, one-thousandth of an inch. Thus the indicia on surface 65 may be used for adjustments between zero and fifty-thousandths of an inch. The end 6! of the thrust member 55 engages flatly against the end 58 of member 54 and provides sufficient friction to retain member 54 in any adjusted position.

An additional housing sleeve 52 is carried upon the sleeve 45 and provided with a counterbore 63 for housing a compression spring 54 to urge the thrust member 59 toward the right in Fig. 3. Housing sleeve 62 may be secured to sleeve 46 by providing a threaded bore 65 which passes through the sleeves ME and 52, and is adapted to receive adocking screw 66. Locking screw 65 has a knurled head El and is adapted .to be used to secure the entire head 42 on the dummy valve stem 4|. 1

The frusto-conical surface 56 on the membe 54 corresponds substantially to the frusto-conical surface 68 on a replacement valve 69, being at the same radial distance from the center of the dummy valve stem ll as the seat 55 from the center of. the valve stem 69.

When the gauge is placed in the engine with the surface 55 engaging the valve seat, the frusto-conical surface 50 on flange i is inside of the diameter of the valve seat and does not engage the seat. Therefore, the length of the stem and head from the end surface Ml to frustoconical surface 55 determines the length of a valve which should be used on that seat.

One of the objects of the present gauge is to provide automatically for the desired amount of clearance. This may be done by setting the rotatable member 5 3- so that the scale on surface 5!! indicates in connection with the marker line or pointer '50 the desired clearance.

with two parts having adjacent inner and outer frusto-conical surfaces, one of said frusto-conical surfaces being spaced axially with respect to the other by an amount equal to the desired clearance of a valve stem, and said frusto-conical surfaces being spaced radially from each other, said stop surfaces being located to engage the inner of said frusto-conical surfaces and to engage the frusto-conical valve seat surface of a valve, said fixture being pivotally mounted on an axis extending substantially parallel to the axis of the grinding wheel, whereby the valve stem may be moved laterally into engagement with the grinding Wheel to effect a trimming'of the valve stem without excessive heating.

6. In a valve stem grinder, the combination of a grinding machine having a grinding wheel mounted upon a rotating shaft, a valve stem grinding fixture movably mounted upon a shaft parallel to the first-mentioned shaft, said valve stem grinding fixture having a body provided with means for supporting a valve stem or a gauge, and said fixture having on the side opposite from the grinding wheel an outwardly projecting shaft fixed thereto provided with a movable stop member, means for clamping said stop member on said outwardly projecting shaft, said stop member having a pair of upwardly extending stops, with stop surfaces at an angle to each other, the angle corresponding to the angularity of the valve seat to be ground in said grinder. I FRANS O. ALBERTSON. 

